Method of regulating the growth of aquatic weeds with pyridine derivatives

Abstract

A method of regulating the growth of submerged and floating aquatic weeds which comprises adding a 3-substituted pyridinemethane, pyridinemethanol, or derivative thereof, to a body of water containing the submerged and floating aquatic weeds to be regulated, in quantities sufficient to regulate the growth of the said submerged and floating aquatic weeds. The disclosure also relates to novel compositions for carrying out the method.

I claim: 
     
       1. A method for inhibiting the growth of submerged and floating aquatic weeds which comprises adding to the water containing said weeds an amount sufficient to provide a growth-regulating and non-herbicidal concentration of a compound of the formula ##STR2## wherein X is hydrogen, hydroxyl, halo, C 1  -C 3  alkoxy, C 1  -C 6  alkylthio, cyclohexylthio, 4-chlorophenylthio, --N(R 3 ) 2 , acetamido, imidazol-l-yl, morpholino, or cyano; R 1  is hydrogen, C 1  -C 9  alkyl, ethynyl, C 3  -C 6  cycloalkyl, benzyl, phenyl, or monohalophenyl;   R 2  is C 1  -C 9  alkyl, C 3  -C 6  cycloalkyl, cyclohexylmethyl, cyclohexylethyl, phenyl, monohalophenyl, dihalophenyl, 3,4-(methylenedioxy)phenyl, trifluoromethylphenyl, p-cumenyl, tolyl, phenoxyphenyl, phenoxy(C 1  -C 4 )alkyl, benzyl, C 1  -C 4  alkoxyphenyl, pentafluorophenyl, xylyl, 2-thienyl, 3-pyridyl, 1,3-dioxan-5-yl, or 5-methyl-1,3-dioxan-5-yl; and   R 1  and R 2 , when taken together with the carbon atom to which they are attached, form 2,6-dimethylcyclohexan-1-yl, 9-fluorenyl, 10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-yl, 9-xanthenyl, 5H-dibenzo[a,d]cyclohepten-5-yl, or 9-thioxanthenyl;   R 3  is hydrogen or C 1  -C 6  alkyl; and   the nonphytotoxic acid addition salts thereof.   
     
     
       2. The method of claim 1 wherein the growth-regulating and non-herbicidal concentration of the active compound ranges from about 0.25 to about 10 ppm. 
     
     
       3. The method of claim 1 wherein the active compound is of the formula ##STR3## wherein X is hydrogen, hydroxyl or methoxy; R 1  is hydrogen, C 1  -C 8  alkyl, C 3  -C 6  cycloalkyl, or phenyl;   R 2  is C 1  -C 8  alkyl, cyclohexylmethyl, cyclohexyl, phenyl, 4-fluorophenyl, 4-chlorophenyl, 4-methoxyphenyl, p-tolyl, or 4-phenoxy-n-butyl;   R 1  and R 2 , when taken together with the carbon atom to which they are attached, form 9-fluorenyl, 9-xanthenyl, or 10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-yl; and   the nonphytotoxic acid addition salts thereof.   
     
     
       4. The method of claim 1 wherein the active compound is of the formula ##STR4## wherein X is hydrogen, hydroxyl or methoxy; R 1  is C 3  -C 8  alkyl, cyclopropyl, cyclohexyl, or phenyl;   R 2  is C 4  -C 7  alkyl, 4-chlorophenyl, 4-fluorophenyl, 4-methoxyphenyl, p-tolyl, cyclohexylmethyl, phenyl, and 4-phenoxy-n-butyl;   R 1  and R 2 , when taken together with the carbon to which they are attached, form 9-fluorenyl; and   the nonphytotoxic acid addition salts thereof.   
     
     
       5. The method of claim 1 wherein the active compound is of the formula ##STR5## wherein X is hydroxyl; R 1  is isopropyl, cyclopropyl, isobutyl, t-butyl, or phenyl;   R 2  is n-hexyl, phenyl, 4-fluorophenyl, 4-methoxyphenyl, or 4-chlorophenyl; and   the nonphytotoxic acid addition salts thereof.   
     
     
       6. The method of claim 1 wherein the active compound is α,α-diphenyl-3-pyridinemethanol. 
     
     
       7. The method of claim 1 wherein the active compound is α-(4-chlorophenyl)-α-cyclopropyl-3-pyridinemethanol hydrochloride. 
     
     
       8. The method of claim 1 wherein the active compound is α,α-diisobutyl-3-pyridinemethanol. 
     
     
       9. The method of claim 1 wherein the active compound is α-hexyl-α-isobutyl-3-pyridinemethanol. 
     
     
       10. The method of claim 1 wherein the active compound is α-(4-chlorophenyl)-α-isopropyl-3-pyridinemethanol. 
     
     
       11. The method of claim 1 wherein the active compound is 3-pyridyl diphenylmethane. 
     
     
       12. The method of claim 1 wherein the active compound is α-isopropyl-α-(4-methoxyphenyl)-3-pyridinemethanol. 
     
     
       13. The method of claim 1 wherein the active compound is α-(t-butyl)-α-(4-fluorophenyl)-3-pyridinemethanol.